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I had a few hours to work on my TPMS retrofit. I have completed most of the tasks, but I ran into an issue with connecting to the CAN block under the dash. I found two posts in the thread that discuss this issue.
Jakes states, "The CAN block. Unsnap the corner closest to the tire, it is on a weird angle...but that end with disengage and allow the block to pop out. Disengage the lower holding tray. Now, you will see to use a small trim stick, or rounded tiny screw driver and "open" the slot tang you want to snap the CAN wire end into - you do not just plug it in. You have to "open" it."
dmarciano provided some additional information, "The canbus hub is sliced sidewards to be removed and then to insert the new plug you have to remove some guard it has, be careful I broke mine and I had to fix the plastic with my soldering iron before getting it back there."
Will someone who has done this work take a look at the attached photos and provide a bit more detail on how to prepare the CAN Block to accept the connector. I tried everything I could think of and feel like I am missing something basic. I stopped before I broke anything, but I would like to complete this work soon.
You are almost there, you see on both sides you have a lock on each? You have to carefully release those locks and you will be able to plug your connector once that is released, then you just lock it back and and slice it back where it should stay
I think I have one at my man cave because I got two from a crashed c230 some time ago to replace my broken one, so I can make a short video releasing the lock in a few days.
Originally Posted by KevinH2000
I had a few hours to work on my TPMS retrofit. I have completed most of the tasks, but I ran into an issue with connecting to the CAN block under the dash. I found two posts in the thread that discuss this issue.
Jakes states, "The CAN block. Unsnap the corner closest to the tire, it is on a weird angle...but that end with disengage and allow the block to pop out. Disengage the lower holding tray. Now, you will see to use a small trim stick, or rounded tiny screw driver and "open" the slot tang you want to snap the CAN wire end into - you do not just plug it in. You have to "open" it."
dmarciano provided some additional information, "The canbus hub is sliced sidewards to be removed and then to insert the new plug you have to remove some guard it has, be careful I broke mine and I had to fix the plastic with my soldering iron before getting it back there."
Will someone who has done this work take a look at the attached photos and provide a bit more detail on how to prepare the CAN Block to accept the connector. I tried everything I could think of and feel like I am missing something basic. I stopped before I broke anything, but I would like to complete this work soon.
Thanks for your reply - and your caution about possibly breaking the part. I hope you have an opportunity to post a video because I tried every way I could think of to open the block without success.
I won't be able to work on this again until the weekend. For now, I'm guessing that I will need to pull the locks away from the block. I tried that, but I was afraid to use too much force.
If I've learned one auto-repair lesson, it is: If you are using a lot of force, you are probably using the wrong technique or something is about to break.
I'm glad I have the option of asking for help on the forum. It made it easier to stop and ask for help before I broke something.
I feel the same way, parts are designed to work as designed...
I recall there being a bar/tab to release then you can add to the distributor block. I also remember messing with it longer than I thought appropriate- then, pop, it unlocked with not too much force...
I have worked under the dash...
but my TPMS harness is connected under the threshold...image attached...so if you don’t want to be uncomfortable on your back, try that location...there was one small “loop” to feed the wire thru at or near the base of the B pillar FYI if you want it all routed and in OEM channels.
I only have a CAN C distributor loose as pictured...
The picture is small and loses detail when I enlarge it. However, based on what I can see, it looks like the CAN block opens by pushing the two ends out and then away from the block.
I'm planning to make another attempt on Sunday afternoon.
Jake's photo and instructions were helpful. I also found these instructions which provide another option:
To detach connectors the block cover has to be removed. Insert a flat head jeweler's screwdriver to lift the latches on each side. It helps when you use masking tape to tape the screwdrivers to the side of the block to prevent the jeweler's screwdrivers from falling off. Then gently pry off the cover (upward) with another small flat head screwdriver. It's better to pry off from one end and then the other.
This photo shows the two parts of the CAN Block:
As usual, it was simple once I determined the correct method. My only true skill as a mechanic is persistence.
I dropped off the programming instructions at my independent mechanic's shop on Wednesday. He told me that he should be able to use his STAR system for the programming. I also need to have a tire pressure sensor put into the right front tire. (That sensor failed the day after I had my new tires installed.)
I put my TMPS retrofit on hiatus while dealing with other more pressing matters. In the interim, another board member (Jake/BF_JC230) and I picked up a STAR diagnostic system through an auction and I decided to tackle the coding myself. Here's an update.
Mercedes built my car in September 2004 and that may affect the outcome of this project. I followed the instructions on the initial post (TPMS in DAS - Step by Step). When I arrived at the instructions on page 4 of the document, I found that my menu did not have an option for "Tire Pressure Monitor." Instead, I have a selection for "Tire Pressure Loss Warner."
I'm planning to change this setting from "Not Present" to "Present" and see if that will give me a warning if I change the air pressure in one of the tires. This would be similar to what Jake reported in the last two posts.
I would appreciate any feedback before I make the change. I would like to avoid doing any permanent damage.
KevinH, Which hardware did you add for your TPMS retrofit?
It looks like you have a W211 - but in my 2005 C230K Sport Sedan, no hardware was needed for the basic system. A fellow member on here simply coded my car for it and it worked for the rest of the time I owned the car. I saw the warnings like shared above several times due to tire pressure issues. This was 10 years ago now. My 2005 had a build date of 1/25/2005.
Pics are from 2011.
Last edited by LILBENZ230; 05-10-2020 at 06:16 PM.
Thanks for the replies. I won't have time until tomorrow night to use DAS again - it is time to celebrate Mother's Day. (I spent an hour fixing my front SAM and asking for more than one victory a day may be pressing my luck.)
I’ve re-read this thread and I think the challenge I am facing is that my car can support the tire pressure warning system, but not tire pressure monitoring. Based on some pages that came up when I searched on the term “Mercedes tire pressure warning” and LILBENZ230 comments in post #94 I didn’t need to add the tire pressure monitors or the module I connected to the rear SAM and the CANBUS.
I think the system I can activate works by using the anti-lock brake sensors to determine whether any wheel is turning more rapidly than the others. A tire that loses air has a smaller circumference than the other tires and it revolves slightly faster. The system reads this and sends a warning. It is not as precise as the TPMS that the original poster was able to activate, but it may save me from getting on the highway with a tire that’s about to fail.
I changed the setting to the one Jake shows in post #93. I will be driving the car to work tomorrow and I will report on the results.
Friday or Saturday I will be performing my monthly tire pressure checks on my fleet of four cars. I expect that I will be adding a few pounds of air to at least one tire. I'll be interested to see whether that triggers a warning.
Like Jake, I have tire pressure monitors in each tire and the receiver is hooked into the wiring. If someone with a car of mine and Jake's vintage (2005 or earlier) is starting this project, I recommend that they see what happens if they change the "Tire Pressure Warner" setting to present before installing the sensors and receivers.
Last edited by KevinH2000; 05-12-2020 at 09:11 PM.
I didn't have any warnings or messages on my commute today.
I think the system that Jake and I have is an indirect system. See this article for a detailed explanation: Indirect TPMSThe article includes a list of cars with indirect systems: Indirect TPMS applications include:
Mercedes C-Class 2007
Mercedes SLK 2005-‘07
I assume that Mercedes added the capability for a TPMS in the 2005 facelift models in anticipation of the U.S. safety standard that was set to go into effect in 2007. Mercedes may not have turned the system on in the 2005-2006 model year cars in order to avoid warranty claims for defective systems or because they didn't want to handle calls from customers regarding warnings on the dash. My wife's 2005 Toyota Highlander has an indirect system which has always been active. There may be a lesson in the difference between Toyota and Mercedes approach to this issue.
The OP had a 2007 C350 and it appears that Mercedes was in the process of changing over from the indirect to the direct systems during that time period. The direct monitoring systems must be more expensive to install, so Mercedes may have used an indirect system for as long as it could.
I'd like to be able to figure out how to add the direct TMPS. That would appear to require an update to the EZS-Electronic ignition switch module. I would need to know a lot more about that module before I made a major change to it.
12-01-2019, 11:46 PM
